It is planned to continue our research program during the ooming years in the same general areas of investigation in which this project has been conducted over the preceding 15 years. The research will be aimed broadly, as in the past, at the neural basis of perception, learning and memory; the developmental patterning and regeneration of nerve connections, and aspects of cerebral organization and hemispheric specialization and interaction utilizing the split-brain approach. The projected research is focused around several somewhat distinct projects that involve different procedural approaches and different animal species as follows: (a) studies of cerebral function in human patients with complete and partial sections of the forebrain commissures, hemispherectomy, agenesis of the corpus callosum, and related unilateral lesions, (b) studies on split-brain monkeys and cats with special emphasis on analytic experimental surgery in the visual system, (c) studies on nerve regeneration, development and maturation in lower vertebrates and in neonate kittens with concern for neurospecificity and functional plasticity, (d) studies on memory consolidation and learning in newly hatched chicks. The balance of emphasis on these different projects will be much the same as indicated below in the abstracts of research during the preceding year.